Background
Aortic stenosis (AS) is the most common cause of cardiac valvular replacement surgery. During the last century the etiology of AS has undergone transitions in developed countries, from rheumatic heart disease to a degenerative calcific etiology. Although a familial component has been described for a subset of cases with a bicuspid valve, data is limited on the overall familial aggregation of this disease.
Methods and Results
Contemporary information on 6,117,263 Swedish siblings, of which 13,442 had a clinical diagnosis of AS, were collected from the nationwide Swedish Multi-generation Register and the National Patient Register. A total of 4.8% of AS cases had a sibling history of AS. Having at least one sibling with AS was associated with a hazard ratio of 3.41 (95% CI=2.23–5.21) to be diagnosed with AS in an adjusted model. Individuals with more than one sibling with AS had an exceptionally high risk (hazard ratio=32.84) but were uncommon (34 siblings from 11 sibships). In contrast, spouses of subjects with AS were only slightly more likely to be diagnosed with AS compared to subjects without spousal AS (hazard ratio 1.16 for husbands and 1.18 for wives).
Conclusions
A sibling history of clinically diagnosed AS was associated with increased risk of AS. Spouses of AS patients only had a modest risk increase, suggesting that shared adult environmental factors contribute less to the development of AS than genetic factors.